Commit fd49c81f authored by Gavin Shan's avatar Gavin Shan Committed by Alex Williamson
Browse files

drivers/vfio/pci: Fix wrong MSI interrupt count

According PCI local bus specification, the register of Message
Control for MSI (offset: 2, length: 2) has bit#0 to enable or
disable MSI logic and it shouldn't be part contributing to the
calculation of MSI interrupt count. The patch fixes the issue.
Signed-off-by: default avatarGavin Shan <>
Signed-off-by: default avatarAlex Williamson <>
parent b13460b9
......@@ -197,8 +197,7 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
if (pos) {
pos + PCI_MSI_FLAGS, &flags);
return 1 << (flags & PCI_MSI_FLAGS_QMASK);
return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
} else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
u8 pos;
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